Tips on Koi Ponds From A Professional Landscaper

A beautiful Koi pond in a well-designed landscape can provide great beauty and enjoyment. There is much more involved than digging a hole, installing a liner and boulders and then adding fish. The vast majority of homeowner and landscaper installed koi ponds are done incorrectly. Many ponds are built with the Koi as an afterthought. Once the homeowner adds fish and then likes them they wish their pond was bigger. A well designed pond is actually much easier to maintain and provides much more enjoyment. We have twenty years’ experience building Koi ponds in the Atlanta area and have learned a lot over the years. We wish to share what we have learned for the benefit of the industry. We see too many dirty ponds that leak and give professional landscapers a bad image.

About Koi

Adult Koi can reach 30 inches in length. I have seen Koi reach that size in small ponds, debunking the theory that the fish will never grow in a smaller pond. A Koi’s growth will be retarded by poor water quality, however. Good water quality is more difficult in smaller ponds. The average lifespan of Koi is 50 years, but their lifespan can exceed 100 years. Koi can be trained to eat from your hand. Happy Koi will swim to meet you to be fed whenever you approach the pond. Some individual Koi have been valued at more than $ 100,000. Koi should not be fed when the water temperature drops below 50 degrees. Chlorine from tap water is harmful to Koi and you must use a DE chlorinator chemical when changing water or filling a new pond. Koi in good water quality will grow three to four inches per year.

This Koi pond has a high density of fish. It is supported by two skimmers, a bottom drain, two bio falls filters, a pre filter and a bead filter and an Ultraviolet sterilizer. The bottom of the pond is mostly liner with a few boulders. It does not have gravel to make keeping it clean easier and less work.

Koi Pond Size and Depth

A good Koi pond should have at least 175 Square feet of surface area. 12 feet by 16 feet or 10 feet by 20 feet are good starting points. This provides enough room for the fish to swim and enough surface area for oxygenating the water. The Depth should be 4 feet 6 inches to 5 feet deep. The extra depth provides better temperature stabilization for the fish as well as evasion from predators. A minimum depth should be 30 inches. Artistic Landscapes does build 1 foot deep shallow areas for pond plants and breeding areas. Ponds can be deeper but it becomes more difficult to clearly see the fish at 7 and 8 foot depths.

Locating the Koi Pond

Locate the pond where you will get the maximum enjoyment from viewing it. Don’t put the pond in an area where rain runoff will run into the pond. You don’t want fertilizer, debris and muddy water to get into your pond. A heavy water flow could wash the fish out of the pond altogether. A partially shaded area is also ideal as the fish don’t like to be in the sun all day. They will seek shade. Pond plants do require some sun.

Koi Pond Liner

Artistic Landscapes uses a fish safe 45 mil for the pond. It is important to not cut the liner too small, especially in the water fall area. We use a double liner in the waterfall and under all boulders. A small hole can create leaks that add to your water bill. Constantly adding water to replace water lost via a leak adds chlorine to the water which is harmful to the fish. More expensive, ponds can also be built out of shot crete or gunite, similar to a swimming pool.

Filtration for Koi Ponds

Water quality is paramount for the health of your fish and your viewing pleasure. No one wants sick fish or green water where you can’t see your fish. A good Koi pond should have two skimmers and a bottom drain. We use a bead filter that is easy to backwash and most importantly provides a great area for beneficial bacteria to colonize to prevent the buildup of Ammonia, which will kill your fish. The waterfall provides aeration. Small pools in the waterfall can provide areas for plants which planting pond plants that also will filter the water. Providing areas in your filtration system for bacteria to colonize is very important. This goes to the nitrification cycle.

Oxygenation of Koi Ponds

Your fish and the beneficial bacteria in your filtration system need oxygen. Hot weather and algae blooms of green water decrease oxygen levels in the pond. Oxygen levels in the water are highest in the evening and the lowest at dawn. Lack of oxygen can stress or kill your fish. We use waterfalls and air stones run by a small air pump to maximize the dissolved oxygen levels in the water. We also use an ultraviolet Sterilizer to keep algae blooms in the water (this does not prevent string algae) from developing. Algae robs your water of oxygen at night. Carbon dioxide levels peak at dawn. They are harmful to your fish. Carbon dioxide buildup is created from plants, breathing fish and decaying plant material such as tree leaves. Keep your pond clean.

We recommend that you have a backup pump for your pond so if your pump fails you can replace it quickly. Air stones run by an air pump can also keep air in the water. If you turn off your pump the powers the filters, the beneficial bacteria in your filters will die. Large doses of chlorinated water will have the same effect.

Water Changes

Water changes are important for healthy fish and a healthy living environment. City water from your hose has chlorine which is harmful or even fatal to your fish. You must use a DE chlorinator chemical available at all pond stores when changing the water. You should change on the following schedule.

Once per week 10 percent change or

Once every two weeks 20 percent change or

Once every three weeks 30 percent change.

Water changes remove pollutants such as phosphates and proteins which are harmful to fish. Topping off the pond from evaporation loss is not a water change. The purpose of the water change is to remove the build up of harmful elements from the water. After doing a water change with dechlorinated water, you will notice that the fish become more active.

While it is not outside the realm of a DIY project, building a Koi Pond is a project best left to aprofessional landscaping company that understands, not only the construction basics but how to design and maintain a pond for the Atlanta climate.